The counterculture's greatest political expression was protesting which war?

The counterculture's greatest political expression was protesting against the Vietnam War.

Counterculture was a movement developed during the 1960s. The people who were part of the counterculture movement were known as 'hippies' and they all opposed to the conventional principles of society. Although counterculture supported many causes, such as the Second-wave Feminism and the Civil Rights Movement, it was mainly an anti-war movement. Members of counterculture raised their voices in many anti-war protests, where they used to burn draft cards and wave Viet Cong flags in order to promote peace over war.